User blog:Corvus coracis/Life, the Universe, and Everything – 1: We Know Nothing
So, I've decided to start a blog over on the forum called Life, the Universe, and Everything. I stayed up for probably way too long last night finishing this, but anyway, it's already on the forum, here. I'm going to be writing about just a bunch of random stuff, whatever interests me. Here's my first post. So, like most of us, I love the Drake Equation, and it has its uses, but it also has its downsides. For example, we can calculate the rate of star formation in the galaxy, or even the percent of Earth-like planets orbiting stars, but ultimately, by the time we figure out any further factors the equation will be useless, because we will have already made contact. Another example. It doesn’t matter whether we happen to get the exact figures just by chance, it still comes out as an overall estimate of the number of advanced civilizations in the galaxy, and it certainly doesn’t in any way whatsoever predict where civilizations are going to be. What we need is direct evidence. Now, while radio signals are great and all, in the midst of much more powerful sources of radio emissions, all civilizations may get lost over interstellar distances. Not to say we can’t detect this. I’m sure that within a few hundred light years of Earth, our signals are clearly visible. Except… They might as well just be interpreted as a neutron star. Now, a neutron star popping out of nowhere when there was clearly no supermassive star previously is obviously impossible. So any civilization even a fraction older than us (perhaps even younger, accounting for the delay of light speed) would be able to tell. But, for all they know, they might be the only civilization they know of, and it could be accounted for by an extremely rare, but natural, phenomenon which only they are aware of. We know nothing. This is, of course, just an example of something that could stand in the way of interstellar communication. There is no evidence whatsoever that a radio-emitting object could pop out of nowhere. But there is another problem. The Drake equation still works, but only on an order or two of magnitude. And modern estimates tend to place the number of civilizations on the order of magnitude of less than 100. So the amount of distance required for communication is so great that signals would be lost, or, just as bad, if not more disappointing, take so long to travel that the civilization would be gone. I feel, intuitively, that there can only be a dozen or so civilizations in the galaxy. Any more and it would be dumbfoundingly obvious that we are not alone. This is what is allotted for in the dimensions of the Milky Way. There are, in my opinion, two things that have not been accounted for in the Drake equation. The first is more of a technicality, and could easily be accounted for by changing the definition of one of the factors. That is the fact that an evolving species, whose rules of survival and adaptation (although not the chemical way that they function) cannot be too different from our own, must mutate due to high radiation. This is not a thing of chemical reactions. This is because things like gamma radiation ionize any atom that they encounter. As a consequence, all organisms in the cosmos should mutate due to high levels of gamma radiation. Therefore, ordinary adaptation is impossible near the center of the galaxy, or in globular clusters, and perhaps even in the denser parts of the spiral arms. The Drake equation does not account for place in the galaxy, further justifying so few civilizations that contact is impossible, because of an inevitable blockade between us and them over these distances. The second problem is completely unaccounted for, and means that the Drake equation is wrong. Plain wrong. We have developed orbiting a star which evolved in the last third of the timespan of the universe. This intuitively makes us think that any beings which evolved on stars older than the sun must be superior to us. Except, there are a lot of problems with this view. Firstly, all life must be orbiting a star not too much larger or smaller than the sun, because of the aforementioned radiation. So no stars will have life spans much longer than the current age of the universe. And we have only about half of this time to evolve. At first, the chaos of a developing system will make life impossible. Then, for a maximum of, say, six billion years, life can arise and evolve. Anything surviving past this point cannot become advanced because, well, radiation. And also heat. I’m not going to do a calculation on how long evolution would on average take to create us. But I am going to do an overview on the major events in evolutionary history. Firstly, the thought of reproduction, of self-replicating with the intention of doing so, is, if you think about it long enough, total insanity. And then the fact that it actually changes in response to things is double total insanity. Nothing does that. And keep in mind I am using a loose definition of life, excluding anything about cells or even organization. Then, we see the evolution of metabolism, turning materials and sunlight into energy. Admittedly, this is what completely natural things do, so not so amazing. But there is a bit of a completely hidden catch. That these early organisms gave off such a useful molecule as oxygen into the atmosphere as a waste product. If they used oxygen, we would be screwed, and so would they, because on early Earth, the atmosphere was less than 1% oxygen. And now, 2 billion years ago, we see an event occurring that blows my mind entirely. Sexual reproduction. No, not intended to sound weird at all. But that’s aside from the point. The evolution of sexual reproduction is the evolution of evolution. That’s right, somehow, it took only 1.5 billion years to evolve something which aids further evolution. Now, even in the cosmic timescale, 1.5 billion years is a fairly long time. But this innovation has such unexpected and such delayed consequences that it was, at least in my opinion, in no way whatsoever, the result of natural selection. It was the result of chance. Sexual reproduction clearly produces offspring far less quickly. It’s a miracle that sexually reproducing organisms managed to survive at all. Even today, asexual organisms reproduce faster. The fact that the vastly outnumbered primitive cells survived is extremely important. And while certainly not the last important innovation of life on Earth, it was the pivotal one. Say that sexually reproducing organisms mutate around 30% faster. This is not an actual estimate, but just for the sake of demonstration, we will use it. At this point in history, a 30% difference in the speed of evolution allowed us to avoid the solar apocalypse. If animals were asexual, the Cambrian explosion would have occurred just before the Earth became uninhabitable. We could just as well be an asexual species, and have the same intellect and behavior. But we just wouldn’t evolve in time. And sexual reproduction is a very required particular manner of reproduction, too. Say horizontal gene transfer mutates 15% quicker than asexual reproduction. Perhaps the dinosaurs would have gone extinct because of the solar apocalypse, rather than the asteroid. Remember the Great Oxygenation Catastrophe? Now, as early eukaryotes begin to use the oxygen from this event, their metabolisms become more efficient. Animals could not evolve if the first organisms used oxygen, or the later ones didn’t. Now, the evolution of eukaryotes themselves or that of multicellular organisms is not all to amazing. It is just several organisms working together to survive. This is a logical and, frankly, probably consequence of evolution. As we get into the Cambrian explosion, we see the first chordates evolving a more complex nervous system. This is essential to our evolution, because if the central nervous system was not created so early in our ancestors’ evolution, the evolution of intelligence would take far longer. Additionally, with such an important system centered in a single line, it prompted the evolution of a skeleton, again essential for any terrestrial animal of our size. Which brings us to the fact that fish just happened to become so successful that some were pushed out of the water by other fish. Is being terrestrial essential to our intelligence? No. The dolphins, for all we know, might have just as much capacity as us. But the last factor of the Drake equation, the fraction of communication, requires us to look to the stars, something which an aquatic species cannot do. The evolution of amniotism (new word!) is to be expected, however pivotal. There is nothing special at all either about the evolution of hair. But one of the most looked over points in our evolution is another important and unlikely one. That is the evolution of milk. It is seen as an obvious advantage. But the resources contributing to raising offspring are at first seen as a waste. While this was probably not the case in the earliest mammals, this definitely lead to something only mammals and a few select birds do: learn. Nextly, the dinosaurs go extinct. Not too unlikely, although the timing was uncanny. Mammals had reached the exact point in their evolution where they finally could diversify if they were allowed to. Frankly, the evolution of bipedality is kind of a sad thought to begin with. If we had evolved more limbs, we would probably never need to go bipedal but instead use a much easier tactic known as centaurism, involving the repurposing of limbs without the changing of stance. But we were still able to make our way. The evolution of tools and the evolution of brains is not unique to us. So I’d say that this is a likely step in our evolution after we have gone so far. But all of these other animals, whether they are ravens, dolphins, or apes, share a very similar history to us. So, do I think that there are many civilizations in the galaxy? No. Not at all. The odds of there being more than a dozen in the entire galaxy are probably less than that of an advanced raven civilization evolving if we were to go extinct. But this is not the point. The point is that the odds of us being the first civilization in the entire galaxy are strikingly high. I would argue that it’s even probable that we are among the first five civilizations in the history of the galaxy. The Drake equation does not account for how long intelligent life takes to evolve. It only accounts for how long it lasts. It’s time for the decades-old equation to receive a modification. Prepare for my next blog, which is exactly about that topic: how we can modify the Drake equation so that it works in theory. While we still don’t have values for most of the factors, at least a new equation might help us really put things into perspective. Category:Exobiology Category:Life, the Universe, and Everything